This proposal seeks support to examine ancillary data being collected in a prospective, observational cohort stud of non-disabled, older women to evaluate and begin developing an instrument to reliably measure cognitive activity. The specific aims are to: l) evaluate and validate the derivative scales of our cognitive activity measures, frequency, intensity, and breadth, and 2) to use the rich data set available in the Women's Health and Aging Study (WHAS) II to begin to develop a conceptual framework of demographic and health characteristics that may mediate associations between cognitive activity and the long-term maintenance of cognitive fiinction. Addressing these objectives will provide insight into the potential benefits derived from regular cognitive activity and help determine whether there is a need for greater promotion of social institutions that enhance older adults' opportunities for cognitively stimulating activity. Study participants are a population-based sample of 436 community-dwelling women ho were 70-80 years of age at baseline and cognitively and physically high functioning in 1994-95 and throughout a 3-year follow-up. They have completed 3 comprehensive examinations, each 18 months apart, which include extensive questionnaire about participation over the past year in cognitive activities. Examinations are performed the Functional Status Laboratory of the Outpatient General Clinical Research Center at Johns Hopkins, and include comprehensive assessment of cognition, physical function, and mental and physical health history. Because the WHAS II has obtained funding for continued assessment of the natural history of functional decline, I anticipate that results obtained from this grant will propel and guide additional research on the role that cognitive activity ma lay on preclinical declines in both cognition and in everyday physical functions. It will also provide insights for targeting at-risk groups and for developing effective, large-scale intervention trials.